[Fe(Phen)(CN)4]-: A Versatile Building Block for the Design of Heterometallic Systems. Crystal Structures and Magnetic Properties of PPh4[Fe(Phen)(CN)4]·2H2O and [{Fe(Phen)(CN)4}2M(H2O)2]·4H2O [Phen = 1,10-Phenanthroline; M = Mn(II) and Zn(II)]
- 27 March 2001
- journal article
- research article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 40 (9), 2065-2072
- https://doi.org/10.1021/ic001241a
Abstract
The mononuclear PPh4[Fe(phen)(CN)4]*2H2O (1) complex and the cyanide-bridged bimetallic [[Fe(phen)(CN)4]2M(H2O)2]*4H2O compounds [M = Mn(II) (2) and Zn(II) (3); phen = 1,10-phenanthroline; PPh4 = tetraphenylphosphonium cation] have been synthesized and structurally and magnetically characterized. Complex 1 crystallizes in the monoclinic system, space group P2(1)/c, with a = 9.364(4) A, b = 27.472(5) A, c = 14.301(3) A, beta = 97.68(2) degrees, and Z = 4. Complexes 2 and 3 are isostructural and they crystallize in the monoclinic system, space group P2(1)/n, with a = 7.5292(4) A, b = 15.6000(10) A, c = 15.4081(9) A, beta = 93.552(2) degrees, and Z = 2 for 2 and a = 7.440(1) A, b = 15.569(3) A, c = 15.344(6) A, beta = 93.63(2) degrees, and Z = 2 for 3. The structure of complex 1 is made up of mononuclear [Fe(phen)(CN)4]- anions, tetraphenyphosphonium cations, and water molecules of crystallization. The iron(III) is hexacoordinate with two nitrogen atoms of a chelating phen (2.018(6) and 2.021(6) A for Fe-N) and four carbon atoms of four terminal cyanide groups (Fe-C bond lengths varying in the range 1.906(8)-1.95(1) A) building a distorted octahedron around the metal atom. The structure of complexes 2 and 3 consists of neutral double zigzag chains of formula [[Fe(phen)(CN)4]2M(H2O)2] and crystallization water molecules. The [Fe(phen)(CN)4]- entity of 1 is present in 2 and 3 acting as a bridging ligand toward M(H2O)2 units [M = Mn(II) (2) and Zn(II) (3)] through two cyanide groups in cis positions, the other two cyanide remaining terminal. Two water molecules in trans positions and four cyanide-nitrogen atoms from four [Fe(phen)(CN)4]- units build a distorted octahedral surrounding Mn(II) (2) and Zn(II) (3). The M-O bond lengths are 2.185(3) (2) and 2.105(3) A (3), whereas the M-N bond distances vary in the ranges 2.210(3)-2.258(3) A (2) and 2.112(3)-2.186(3) A (3). The structure of the [Fe(phen)(CN)4]- complex ligand in 2 and 3 is as in 1. The shorter intrachain Fe-M distances through bridging cyano are 5.245(5) and 5.208(5) A in 2 and 5.187(1) and 5.132(1) A in 3. The magnetic properties of 1-3 have been investigated in the temperature range 2.0-300 K. Complex 1 is a low-spin iron(III) complex with an appreciable orbital contribution. The magnetic properties of 3 correspond to the sum of two magnetically isolated spin triplets, the magnetic coupling between the low-spin iron(III) centers through the -CN-Zn-NC- bridging skeleton (iron-iron separation larger than 10.2 A) being negligible. More interestingly, 2 exhibits one-dimensional ferrimagnetic behavior due to the noncompensation of the local interacting spins (S(Mn) = 5/2 and S(Fe) = 1/2) which interact antiferromagnetically through bridging cyano groups. A comparison between the magnetic properties of the isostructural compounds 2 and 3 allow us to check the antiferromagnetic coupling in 2.Keywords
This publication has 57 references indexed in Scilit:
- From ferromagnets to high-spin molecules: the role of the organic ligandsPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1999
- Structures, Ferromagnetic Ordering, Anisotropy, and Spin Reorientation for Two- and Three-Dimensional Cyano-Bridged Mo3±-Mn2± CompoundsMolecular Crystals and Liquid Crystals, 1999
- New Molecule-Based Magnets: From Hexacyano to OctacyanometalatesMolecular Crystals and Liquid Crystals, 1999
- A Chromium−Vanadyl Ferrimagnetic Molecule-Based Magnet: Structure, Magnetism, and Orbital InterpretationInorganic Chemistry, 1999
- Structure and Magnetism of a Bimetallic Pentanuclear Cluster [(Ni(bpm)2)3(Fe(CN)6)2]·7H2O (bpm = Bis(1-pyrazolyl)methane)). The Role of the Hydrogen-Bonded 7H2O “Cluster” in Long-Range Magnetic OrderingInorganic Chemistry, 1997
- A New Bimetallic Ferromagnet, [Ni(en)2]3[Fe(CN)6]2.cntdot.2H2O, with a Rare Rope-Ladder Chain StructureJournal of the American Chemical Society, 1994
- High-TC molecular-based magnets: a ferromagnetic bimetallic chromium(III)-nickel(II) cyanide with TC = 90 KJournal of the American Chemical Society, 1992
- Magnetism and electronic structure of a series of encapsulated first-row transition metalsInorganic Chemistry, 1990
- Mössbauer Study of Soluble Prussian Blue, Insoluble Prussian Blue, and Turnbull's BlueThe Journal of Chemical Physics, 1968
- Mixed Ligand Complexes of Iron(II) and (III) with Cyanide and Aromatic Di-iminesJournal of the American Chemical Society, 1960